Retriever for auger earth boring tools



Jan. 16, 1962 R. E. HENRY ETAL 3,017,216

RETRIEVER FOR AUGER EARTH BORING TOOLS.

Filed March 14, 1960 NVENTORS BY I VK 14 Q United States Patent3,017,216 RETRIEVER FOR AUGER EARTH BORING TOOLS Richard E. Henry andFrank Wash, Port Washington, Wis., assignors to Koehring Company,Milwaukee, Wis., a corporation of Wisconsin Filed Mar. 14, 1960, Ser.No. 14,871 8 Claims. (Cl. 294-86) This invention relates to augerretrieving tools and, more particularly, to a retrieving tool designedto be threadingly coupled to a broken or detached auger section which islocated in a remote and relatively inaccessible location.

In earth boring operations employing an auger, or an auger string, aproblem frequently encountered is that of retrieving a broken auger tipor, on occasion, retrieving an entire section of an auger string whichhas become detached fromthe main string. The problem of broken augersand detached auger sections is particularly applicable when drillingdeep post holes, for example, telephone post holes or holes for pilings.

Various situations arise wherein auger breakage occurs. One of the mostcommon causes for breakage occurs when the auger encounters a solidobstruction, at which time the forces imposed upon the auger string tendto shear the coupling pin between adjacent auger sections. Even wherecoupling pins are frequently replaced, an anger section that has beenused on repeated occasions tends to become weakened due to metalfatigue. Consequently, when an obstruction is encountered the augersection may shear in a weakened area. Another cause of detached augersections results from the use of faulty or improper positioned couplingpins between adjacent sections.

When an auger section breaks, or becomes detached, the operator is facedwith the problem of a practical and economic way to remove the detachedsection. Prior art attempts to solve the aforementioned problem havetaken various forms, however, none of the prior art schemes of which weare aware have provided a rapid and economical means for removing thedetached auger section. Perhaps the most rapid prior art method ofcoping with the problem has been that of abandoning the partiallydrilled hole, leaving the detached tool section therein, andsubsequently drilling a second hole. Such a solution is unsatisfactorynot only because of the lost time involved but also because of theexpense of having to drill a second hole. Additionally, where an entireauger section has become detached from the auger string, the expense ofabantiming the detached section is prohibitive. Another scheme forretrieving a broken or detached auger section has been to arrange asling and attempt to hook the detached or broken section from the groundlevel. This solution is not only time consuming but, more often thannot, it has been found impossible to hook the tool section. Frequentlyit is essential that the hole be drilled in a particular location andwhen this occurs the operator cannot abandon the hole and equipment anddrill a second hole. Thus, he has been formed to excavate to the depthof the broken or detached auger, again resulting in loss of valuabletime and increased expense. On occasion, and where the hole is largeenough, a man is lowered into the hole to secure a line to the broken or.detached section. Such a course of action is not only dangerous butfrequently requires the welding of an eye or ring to the end of thedetached auger section in order to provide something to which a line canbe attached.

Accordingly, it is the general object of this invention to overcome theaforementioned difficulties and to provide an improved tool capable ofretrieving broken and ice detached augers rapidly and at a minimumexpense in use and permits of economic fabrication from readilyavailable materials. In this connection it is an object of our inventionto provide an auger retriever tool that is guided to the broken auger bythe drilled hole.

It is another object of this invention to provide an auger retrievertool that may be connected to and used with drilling equipment alreadyin use and that requires no special apparatus or the expense attendingthe moving of such apparatus to the site.

A more specific object of this invention is to provide an augerretriever tool that may be threadingly coupled to the broken or detachedauger section from a remote point, thereby providing a positive couplingfor withdrawing the auger. Such a retriever obviates any need forlowering a man to secure a line to the broken or detached auger section,thus eliminating a major source of danger.

These and other objects and advantages of the invention are attained bythe construction and arrangement shown by Way of illustration in thedrawing, in which:

FIGURE 1 is a side elevation, partly in section, of an auger retrieverembodying the invention just prior to being threadingly coupled to abroken auger section;

FIG. 2 is a perspective view, partly in section, of an auger retrieverembodying the invention that has been partially threaded on a brokenauger section;

FIG. 3 is a top view, partly in section, taken along the line 33 of FIG.1 and disclosing the torque transmitting member used in conjunction withthe auger retriever; and

FIG. 4 is a bottom view taken along the line 4-4 of FIG. 1.

While the invention has been illustrated and will be described withparticularity in connection with a preferred embodiment, it will beunderstood that it is not intended to be limited to this specificembodiment, but rather to cover such equivalent and alternativeconstructions as may be included within the spirit and scope of theappended claims.

Referring to the drawing there is illustrated in FIG. 1 an augerretrieving tool, indicated at 10, embodying the invention and which hasbeen inserted into a hole 11 that had been bored in the earth 12 by anauger 14. It will be noted that the auger 14, which comprises a centralshaft 15 having a helical flight or blade 16 mounted thereon, isembedded in the bottom of the hole 11 and, as indicated at 18, hasbroken off of the main auger section. The auger retrieving tool 10 hasbeen illustrated in FIG. 1 as in position to engage auger 14 and justprior to engagement therewith.

It will be understood that in order to retrieve a broken ordetachedauger section that has been solidly embedded within the ground,the retrieving tool employed must positively and securely engage thesection so as" to apply thereto the considerable force that must beexerted in order to withdraw the detached section from its embeddedposition.

According to th-e'preferred embodiment of our invention, the augerretrieving tool is provided witha hollow, cylindrical tube or pipe 20,preferably made of steel; The tube is open at one end 21, as has'been'more clearly illustrated in FIGS. 2 and 4. The opposite end of the tubeis partially closed by a plate 22 which is made rigid with the tube 20as by welding about its periphery as indicated at 24. Means are providedfor effecting a driving and supporting connection between the retrieverand the drilling apparatus with which it is to be used. In theillustrative device hexagonal stub shaft 25 is rigidly secured is to beused. The hexagonal stub shaft may vary in size according to the size ofthe auger and the size of the retriever that is to be used. It will beunderstood that the flight extension 28 is secured to suitable rotatablepower driving means (not shown). Radial holes 29 and 30 are formed inthe flight extension and the stub shaft respectively, and serve toreceive a locking pin 31, thus preventing relative axial movementbetween the flight extension 28 and the stub shaft 25.

Rotational movement is imparted to the flight extension 28 from anysuitable power means and is transmitted to the pipe 22 through thedriving connection constituted by the flight extension and the hexagonalshaft. Plate 22 serves as a torque transmitting member for the augerretrieving tool and imparts rotational movement to the tube 20.

In accordance with one of the important aspects of the invention, theauger retrieving tool 10 is provided with means positioned to engage andexert thrust against the bottom surface of the detached auger flight.More particularly, the tool includes a plurality of lugs 32 which aredisposed on and welded to the inner surface 34 of the tube 20. The lugsare arranged in a helical pattern, as has been clearly illustrated inFIGS. 1 and 2, and extend substantially radially toward the axis of thetube. This is the preferred embodiment. It is to be understood, however,that a continuous section of helical flight could be used in place oflugs. The auger to be retrieved has a helical flight or blade 16 havinga predetermined external diameter D and a predetermined pitch P asindicated in FIG. 1. The hollow, cylindrical tube 20 has an insidediameter D, that is slightly larger than the diameter D of the helicalflight, thus allowing the detached auger to be received within the tube.The internal diameter D of the lugs 32 is substantially smaller than thediameter D,, of the auger flight, as can best be seen in FIG. 4. Thus,the tip portions 35 of the lugs 32 define a tubular passage having adiameter D which diameter is smaller than diameter D,, of the augerflight 16 but greater than diameter D of the auger shaft 15, therebyallowing the auger shaft to be received within the aforesaid tubularpassage. Moreover, since the lugs are disposed in a helical patternhaving a pitch P which corresponds substantially to the pitch P of theauger flight, and since the internal diameter of the tube D is greaterthan the external diameter of the flight D,,, it is apparent thatclockwise rotational movement imparted to the retrieving tool causes thetool to be threadingly coupled to the auger section to be retrieved.

Turning to FIG. 2, there is illustrated a broken auger section 14 whichis partially coupled with the auger retrieving tool 10. It will be notedthat each of the lugs 32 extends a substantial distance under theadjacent auger flight 16. As the pitch P,, of the auger flight 16 issubstantially the same as the pitch P of the helically disposed lugs 32,the upper portion of each lug engages the juxtaposed lower portion ofthe auger flight. Thus, when the auger section is to be retrieved and anupward force is exerted on the retrieving tool 10, as indicated by arrowT in FIG. 2, substantially proportionate and equal forces are exerted inan upward direction against the auger flight 16 by each of the lugs 32as indicated by the arrows t. It will therefore be obvious that nosingle concentrated force is exerted against any one portion of theauger flight and consequently the danger of damage to the auger flightis minimized. This is of particular importance when retrieving entireauger sections that have not been broken but merely detached from theauger string.

Referring to FIG. 3, it will be noted that the torque transmitting plate22 has been provided with a plurality of axially disposed openings 36.Such openings provide a passage for fluid, dirt and other foreignmaterials in an upward direction therethrough when the auger retrievingtool is being lowered into a hole. Consequently, in-

gress of the tool into the hole 11 is unimpeded thereby. In like manner,when the tool and the retrieved auger are being withdrawn from the hole,fluid, dirt and other foreign materials can pass downwardly through theopenings 36 and egress of the tool will not be restrained. It will beapparent to one skilled in the art that the provision of openings in thetorque transmitting plate will have particular significance when boringdeep holes to receive pilings and where the holes are often filled, orpartially filled, with water.

In operation, and assuming that an auger section has either broken orbecome detached while drilling a hole, it is merely necessary for theoperator to withdraw the intact portion of the auger string and tosecure the hexagonal stub shaft 25 of retrieving tool 10 within thehexagonal bore 26 of the lowermost flight extension 28. The tool 10 isthen lowered into the hole 11 and guided thereby until it engages thebroken or detached auger section 14. Since the tool 10 is of a diameterslightly larger than the diameter of the auger flight, the tool will inturn be slightly larger than the diameter of the bored hole.Consequently, as the tool is forced into the hole, the hole will, ineffect, be reamed and the earth scraped away from the sides of the hole11 will fall to the bottom thereof. While the external diameter of thetool is not critical so long as the internal diameter thereof is greaterthan the diameter of the auger flight, it will be understood that theretrieving tool should be maintained as small as possible in order tominimize the amount of earth that will be reamed from the sides of thehole. While rotational movement of the tool is desirable during loweringthereof, it is not essential.

When the retrieving tool engages the broken or detached auger section14, rotational movement of the tool causes the tool to be screwed ontothe auger section, thus threadingly coupling the two members together.Rotational movement of the tool is continued until the broken ordetached auger section is fully coupled with the helically disposed lugs32 at which time the upper portion 18 of the broken or detached augersection 14 engages the bottom of the torque transmitting plate 22 andrelative rotation between the retrieving tool 10 and the auger section14 ceases. The flight extension 28 or other similar connect-ing andsupporting means can then be connected to a winch or boom line and thetool and retrieved auger section can be withdrawn from the hole.

While the invention has been described primarily for use in retrievingbroken or detached auger sections from the bottom of a verticallydrilled hole, it will be obvious that the tool is equally susceptible touse in a horizontally drilled hole, or for that matter, any otherangularly disposed hole. Moreover, while the invention has beendescribed in terms of a preferred embodiment, numerous changes might bemade and still fall within the scope and spirit of the invention. Forexample, the torque transmitting plate 22 might take the form of aspider, in which case it would be unnecessary to provide additionalaxial holes therethrough. Moreover, while the helically disposed lugshave been described as being welded to the interior surface of the tube,it will be obvious that they might be secured thereto in other ways, orthey might 'be struck in from the side walls of the tool itself.Additionally, it will be understood that the particular means disclosedfor coupling the retrieving tool It} to the drive means do not form anessential part of our invention and other coupling means could beemployed. Consequently, it is intended that such modifications beincluded within the spirit and scope of the appended claims.

We claim as our invention:

1. For use with earth drilling apparatus, an auger retriever forremoving from a drilled hole a detached auger section and the like ofthe type having a helical blade, said retriever comprising, incombination, a tubular shell, drive means for effecting with thedrilling apparatus a supporting and driving connection for said shell,

and a plurality of lugs secured to said shell and extendingsubstantially radially inward into said shell, said lugs defining asubstantially helical surface for engagement with the bottom surface ofthe helical blade of said detached auger sections.

2. A retriever for removing detached auger sections and the like from adrilled hole comprising, in combination, a tubular shell, drive meansfor inserting said shell into the hole and withdrawing said shell out ofthe hole, torque transmitting means coupling said drive means and saidshell, and means disposed on the inner surface of said shell forthreadingly engaging the detached auger section so that the augersection can be removed from the drilled hole.

3. A retriever for removing detached auger sections and the like from adrilled hole comprising, in combination, a tubular shell, drive meansfor inserting said shell into the hole and withdrawing said shell out ofthe hole, torque transmitting means coupling said drive means and saidshell, means disposed on the inner surface of said shell for threadinglyengaging the detached auger section so that the auger section may beremoved from the drilled hole, and stop means for preventing relativerotation between said shell and the detached auger section when theauger section is threadingly coupled to said shell.

4. In an auger retriever for recovering detached auger sections having ahelical blade thereon, said retriever having a tubular shell, theimprovement which comprises a plurality of inwardly projecting,substantially radial lugs secured to said shell in a helical pattern,said helical pattern having a pitch substantially similar to the pitchof the helical blade, and drive means for imparting rotational movementto said shell for threaded engagement of said lugs with the detachedauger section.

5. A retriever for removing from a drilled hole detached auger sectionsand the like of the type having a helical blade, said retrievercomprising, in combination, a tubular shell having an internal diameterslightly larger than the diameter of the auger blade, drive means forinserting said shell into the drilled hole and withdrawing said shellout of the drilled hole, torque transmitting means interposed betweensaid drive means and said shell, and a plurality of inwardly projecting,substantially radial lugs secured to said shell in a helical pattern ofa pitch substantially corresponding to the pitch of the helical augerblade, said helical pattern defined by said lugs having an internaldiameter substantially smaller than the diameter of the auger blade,said drive means imparting rotational movement to said shell so thatsaid lugs are threadingly coupled to the detached auger section.

6. A retriever for removing from a drilled hole detached auger sectionsand the like of the type having a helical blade, said retrievercomprising, in combination, a tubular shell having an internal diameterslightly larger than the diameter of the auger blade, drive meanselfecting a supporting and driving connection for inserting said shellinto the drilled hole and for withdrawing said shell out of the drilledhole, torque transmitting means coupling said drive means and saidshell, said torque transmitting means having at least one axial openingextending therethrough, and a plurality of inwardly projectingsubstantially radial lugs secured to said shell in a helical patternhaving a pitch substantially similar to the pitch of the helical blade,said helical pattern defined by said lugs having an internal diametersubstantially smaller than the diameter of the auger blade, said drivemeans imparting rotational movement to said shell so as to threadinglycouple said lugs to the auger section for retrieving the latter.

7. A retriever for removing from a drilled hole detached auger sectionsand the like of the type having a helical blade, said retrievercomprising, in combination, a tubular shell having an internal diameterslightly larger than the diameter of the auger blade, drive meanseffecting a supporting and driving connection for inserting said shellinto the drilled hole and for withdrawing said shell out of the drilledhole, torque transmitting means interposed between said drive means andsaid shell, said torque transmitting means constituting a fixed stopwhich serves to prevent relative rotation between said shell and thedetached auger section when said shell is threadingly coupled to theauger section and a plurality of inwardly projecting, substantiallyradial lugs secured to said shell in a helical pattern having a pitchsubstantial-1y similar to the pitch of the helical blade, said helicalpattern defined by said lugs having an internal diameter substantiallysmaller than the diameter of the auger blade, said drive means impartingrotational movement to said shell so as to threadingly couple said lugsto the detached auger section for retrieving the latter.

8. A retriever for recovering from a drilled hole detached augersections and the like of the type having a central shaft wit-h a helicalblade disposed thereon, said retriever comprising, in combination, atubular shell, drive means effecting a supporting and driving connectionfor inserting said shell into the drilled hole and withdrawing saidshell out of the drilled hole, torque transmitting means interposedbetween said drive means and said shell, and means disposed on the innersurface of said shell for threadingly engaging the detached augersection so that the auger section may be removed from the drilled hole,said last named means comprising a plurality of lugs rigidly secured tothe inner surface of said shell, said lugs arranged in a helical patternon said shell and projecting substantially radially into said shell,said lugs having end portions which terminate short of the axis of saidshell so that the end portions of said lugs define a tubular passageextending through said shell and along the axis thereof, said shellhaving an internal diameter greater than the diameter of the helicalblade and said tubular passage having a diameter greater than the augershaft but less than the helical auger blade.

References Cited in the file of this patent UNITED STATES PATENTS2,449,841 Claypool et al Sept. 21, 1948

